Protective circuits of the type mentioned above usually have semiconductor components in the form of Zener diodes in the voltage-limiting circuit components, a corresponding series connection of such voltage-limiting circuit components in turn being connected in parallel to an input of the electronic circuit to be protected. If transient excess voltages occur at the input of the circuit to be protected, a Zener diode polarized in the non-conducting direction with respect to the excess voltage becomes conductive as soon as the excess voltage exceeds an avalanche voltage of the Zener diode. This limits the excess voltage to a value that roughly corresponds to the avalanche voltage of the particular Zener diode, possibly plus a forward voltage of another Zener diode polarized in the forward direction with respect to the excess voltage.